So I just noticed White fuzz like stuff on Ronon.. I have only had him a few days, but he is a gorgeous fish when he flares.. And he was in 1 of the "condo's" of my divided 20L.. So now I have all 4 fish pulled out & in there own quarantined tanks (3 of the 4 of them are in about 1/2 gallon of water in the bottom of 2.5 gal tanks & the last one is currently in a big mason jar). My wife is currently driving back into town to get some bettafix from PetCo. The water there in came from my Sorority tank & none of the girls in there are experiencing any sign of anything wrong. Going to pull out my plants, shrimp & snails now & quarantine them in another large mason jar.. Anything else I should be doing here?

Ack.. Bettafix isn't usually the best thing to use, it has a tree oil chemical in it that has potential to harm their labyrinth organ. Some people use it just fine, but a majority of betta owners will say not to use it. Unsure why it's on the market, but there is the risk using it. Here is the ideal treatment for fungus:

True Fungal Infections
•Symptoms: White cottony like patches on its body or head, Lethargic, Not eating, Clamped Fins, Pale Colors
•Treatment: Conservative: Lower temperature below 76* F and treat with Aq.Salt at 1 tsp/gal. Increase water changes to 100% daily. Replace accurate amount of salt following water changes. Never continue salt treatments for more than 10 days. Medication: If Conservative treatment is ineffective after 10 days or you see the fungus spread rapidly during the course of conservative treatment, move to medication. Add “Fungus Eliminator” by Jungle, API Erythromycin, API Fungus Cure, API Triple Sulfa, OR Mardel’s Maracyn II. Change water every day and add a new dose of the same medication. Continue until all fungus has disappeared.

Make sure it is fungus, a cottony white growth and not excess slime coating which looks similar to fungus, but more translucent and covers more of the body. If it's just excess slime coating, a water change is all that is really needed.

I 1st noticed it following a water change.. Ronon was laying on the bottom of the tank & I could see his little gills moving so I looked close & the only place I saw the cottony stuff was along his back ridge.. It wasn't even to his fins.. None of the other 3 appear to have it, & they are all 4 flaring up & moving just fine right now (since they can see each other better then the normal black mesh allows)

I would go ahead and do 100% daily water changes for a few days while he is in QT and see if that clears him up. If you see it getting worse, or not going away after 3 days or so, then would do the salt treatment. It's hard to tell from this angle, but it looks like slime coat issue to me.

Do a large water change in your main tank before adding anyone back in.

I would go ahead and do 100% daily water changes for a few days while he is in QT and see if that clears him up. If you see it getting worse, or not going away after 3 days or so, then would do the salt treatment. It's hard to tell from this angle, but it looks like slime coat issue to me.

Do a large water change in your main tank before adding anyone back in.

Actually I noticed some of this on his side fins before I left home today & I started a salt treatment with him in QT.. The main tank is completely drained & evertything is going to get a super through cleaning before going back in (was going to have to pull it apart on thursday to install my new internal filter with a hose under teh gravel & dividers for the return anyway so I went ahead & jsut emptied the whole thing now)..

If it weren't for the bright white, I'd say that is excess slime coat trailing above it. It also may be a little bit of both. Either way, I would do the recommended AQ salt treatment, 1 tsp (dissolve prior to adding fish in it) per gallon, daily 100% water changes, normal water conditioner (don't use Stress Coat, since that will also cause excess slime coating at times) and right now you don't want to cause him to create more.
Wouldn't do the salt treatment for more then 10 days, but if you it has gone during the 10 days, continue the treatment for the full 10 days to make sure that whatever was going on, is treated completely.

ok.. I will be doing the complete water change shortly.. It almost seems odd to me though that none of the other boys in his tank have any symptoms at all.. Also Ronon hasn't been eating much if anything.

He may of been ill prior to you bringing him home and the stress from the the move exasperated the illness. Keep an eye on your other guys to make sure that the water didn't carry over the problems to them.
He seems to be clamped up, and with the clamping and how he looks, it doesn't surprise me that he isn't eating much. Once he is feeling better he should start eating again regularly.

(On a side note, I almost freaked out on you lol.. I saw the 20L, and that could easily mean 20Liters, rather then 20L gallons.. was thinking "5 bettas, snails and shrimp in 5 gallons?? (20L = 5G)".. yeah, then I realized you're in Boise and I had a d'oh! moment.. =P )